<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 500px;
            height: 500px;
            background-color: red;
            display: flex;
            /* justify-content: space-around; */
            align-items: flex-end;
        }
       
        div span {
            width: 150px;
            /* height: 50px; */
            background-color: green;
        }
       </style>
</head> 
<body>
    <div>
        <span>1</span>
        <span>2</span>
        <span>3</span>
    </div>
</body>
</html>